Danger in the US: NTSB recommends evaluating 68 bridges for risk of collapse

The U.S. National Transportation Safety Board recommended this week that 30 owners of 68 bridges in 19 states conduct a vulnerability assessment to determine the risk of infrastructure collapse due to a vessel collision.

These requests stem from a report from the ongoing investigation following the collapse of the Francis Scott Key Bridge in Baltimore in 2024.

The NTSB determined that the Key Bridge was not within the parameters established by the American Association of State Highway and Transportation Officials (AASHTO) guide.

During the past year, the board identified 68 bridges designed prior to the adoption of the AASHTO guidelines that do not have a current vulnerability assessment. Recommendations are issued to bridge owners to calculate the annual collapse frequency of their bridges using a specific calculation method.

States that have bridges in need of assessment

The submitted report does not suggest that all 68 bridges are certain to collapse. However, it does believe it is imperative to know if these bridges exceed the "acceptable risk" level in effect in the U.S.

The bridges recommended for evaluation include the Golden Gate Bridge in San Francisco; the Brooklyn and Manhattan Bridges in New York; the Lewis and Clark Bridge between Washington and Oregon; the Chicago Skyway Bridge in Illinois and the Huey P. Long Bridge near New Orleans.

There is a system that classifies bridges as "critical/essential" or "typical." Those considered critical serve as important links in the Strategic Highway Network.

States on the list that have bridges that will be examined are California, Delaware, Florida, Georgia, Illinois, Louisiana, Maryland, Massachusetts, Michigan, New Hampshire, New Jersey, New Jersey, New York, Ohio, Oregon, Pennsylvania, Rhode Island, Texas, Washington and Wisconsin.

Baltimore disaster: Six dead and millions of dollars in losses

The 984-foot, Singapore-flagged freighter Dali was sailing from the Port of Baltimore when it suffered a power and propulsion failure, striking the south pier supporting the center truss spans of the Francis Scott Key Bridge, which subsequently collapsed. Six construction crew members were killed and another was injured, in addition to one person on board.

The NTSB concluded that had the Maryland Transportation Authority (MDTA)conducted a vulnerability assessment of the Key Bridge based on recent vessel traffic, the MDTA would have known that the Key Bridge was above acceptable risk and would have had information to proactively reduce the risk of bridge collapse and loss of life associated with a collision like the one in 2024.

At the time it collapsed, the Key Bridge was nearly 30 times above the acceptable risk threshold for critical or essential bridges.

Other recommendations to avoid future disasters

The NTSB also recommends that the FHWA, the U.S. Coast Guard and the U.S. Army Corps of Engineers establish an interdisciplinary team to provide guidance and assistance to bridge owners in assessing and reducing risk, which could mean infrastructure improvements or operational changes.

It also called for the development and implementation of a comprehensive risk reduction plan if calculations indicate that a bridge presents a level of risk above the AASHTO threshold.